2

AT97SC3201

2015DS-TPM–7/04

A real-time clock function is available using an external battery and crystal. The chip provides

tamper detection if the battery or crystal are removed or tampered with, and the current time

value can be signed by the appropriate internal keys to verify its accuracy. (Contact Atmel for

current status of this option.)

The battery detector can be used without the crystal for lower cost. In this mode, the TPM can

indicate to the system if it has been removed from the PC in any way and can also take

actions internally.

The chip uses a dynamic internal memory management scheme to store from 10 to 20 keys.

Other than the standard TCG commands (TPM_Evictkey, TPM_Loadkey), no system inter-

vention is required to manage this internal key cache.

The TPM is offered to OEM manufacturers as a turnkey solution, including the firmware inte-

grated on the chip. In addition, Atmel provides the necessary driver software for integration

into certain operating systems, along with BIOS drivers. A TCG Software Stack (TSS), also

supplied by Atmel and available under license, provides communication support to any appli-

cation using MSCAPI or PKCS #11 Cryptographic APIs. (Contact Atmel for a complete list of

operating systems supported.)

F u l l d o c u m e n t at i on f o r T C G pri m i t i v es c an be f oun d o n t he T C G W eb s i t e ,

www.trustedcomputinggroup.org. This specification includes only mechanical and electrical

information.